Buffett's Lesson for Keystone and Canada

For a clue to what is going to happen with Canadian oil amid the Keystone XL pipeline battle, take a look at Warren Buffett's latest letter.

The Berkshire Hathaway chief executive writes that BNSF, the railroad his company bought in 2010, now transports 500,000 barrels of oil a day. Much of it comes from the prolific Bakken shale, where production growth has outpaced pipelines. The resulting local glut led the discount between Bakken oil and Brent crude to surge beyond $45 a barrel a year ago (it has narrowed to $19 now).